scholarly journals The Application of Carbon Nanotubes in Magnetic Fluid Hyperthermia

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Grzegorz Raniszewski ◽  
Arkadiusz Miaskowski ◽  
Slawomir Wiak
Keyword(s):  
Magnetic Field ◽  
Carbon Nanotubes ◽  
Biomedical Applications ◽  
Magnetic Particles ◽  
Damage Model ◽  
Alternating Magnetic Field ◽  
Thermal Dose ◽  
Generation Efficiency ◽  
Magnetic Fluid Hyperthermia ◽  
Body Tissues

The aim of this paper is to present the results of the investigation into the applications of carbon nanotubes with ferromagnetic nanoparticles as nanoheaters for targeted thermal ablation of cancer cells. Relevant nanoparticles’ characteristics were exploited in terms of their functionality for biomedical applications and their magnetic properties were examined to determine heat generation efficiency induced by the exposure of the particles to an alternating magnetic field. The influence of the electromagnetic field on the human body tissues was assessed, providing quantitative measures of the interaction. The behavior of a liquid containing magnetic particles, during the exposure to the alternating magnetic field, was verified. As for the application for the ferromagnetic carbon nanotubes, the authors investigated temperature distribution in human liver tumor together with Arrhenius tissue damage model and the thermal dose concept.

Sinusoidal magnetic field stimulates magnetosome formation and affects mamA, mms13, mms6, and magA expression in Magnetospirillum magneticum AMB-1

2008 ◽  
Vol 54 (12) ◽  
pp. 1016-1022 ◽  
Author(s):  
Xiaoke Wang ◽  
Likun Liang ◽  
Tao Song ◽  
Longfei Wu
Keyword(s):  
Magnetic Field ◽  
Geomagnetic Field ◽  
Biomedical Applications ◽  
Magnetic Particles ◽  
Industrial Sector ◽  
Magnetic Pole ◽  
Variable Intensity ◽  
New Approach ◽  
Sinusoidal Magnetic Field ◽  
Magnetospirillum Magneticum

Magnetic particles are currently one of the most important materials in the industrial sector, where they have been widely used for biotechnological and biomedical applications. To investigate the effects of the imposed magnetic field on biomineralization in Magnetospirillum magneticum AMB-1 and to suggest a new approach that enhances formation of magnetosomes, cultures inoculated with either magnetic or nonmagnetic precultures were incubated under a sinusoidal magnetic field or geomagnetic field. The results showed that the sinusoidal magnetic field up-regulated mms6 expression in the cultures inoculated with magnetic cells, and magA, mms6, and mamA expression in the cultures inoculated with nonmagnetic cells. The applied sinusoidal magnetic field could block cell division, which could contribute to a decrease in the OD600 values and an increase in the coefficient of magnetism values of the cultures, which could mean that the percentage of mature magnetosome-containing bacteria was increased. The linearity of magnetosome chains was affected, but the number of magnetic particles in cells was increased when a sinusoidal magnetic field was applied to the cultures. The results imply that the variable intensity and orientation of the sinusoidal magnetic field resulted in magnetic pole conversion in the newly forming magnetic particles, which could affect the formation of magnetic crystals and the arrangement of the adjacent magnetosome.

scholarly journals Investigation on Finishing Characteristics of Magnetic Abrasive Finishing Process Using an Alternating Magnetic Field

Machines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 75
Author(s):  
Huijun Xie ◽  
Yanhua Zou
Keyword(s):  
Magnetic Field ◽  
Magnetic Particles ◽  
Alternating Magnetic Field ◽  
Surface Finishing ◽  
Magnetic Cluster ◽  
Magnetic Abrasive Finishing ◽  
Square Wave ◽  
Finishing Process ◽  
Abrasive Finishing ◽  
The Difference

The magnetic abrasive finishing (MAF) process is an ultra-precision surface finishing process. In order to further improve the finishing efficiency and surface quality, the MAF process using an alternating magnetic field was proposed in the previous research, and it was proven that the alternating magnetic field has advantages compared with the static magnetic field. In order to further develop the process, this study investigated the effect on finishing characteristics when the alternating current waveform is a square wave. The difference between the fluctuation behavior of the magnetic cluster in two alternating magnetic fields (sine wave and square wave) is observed and analyzed. Through analysis, it can be concluded that the use of a square wave can make the magnetic cluster fluctuate faster, and as the size of the magnetic particles decreases, the difference between the magnetic cluster fluctuation speed of the two waveforms is greater. The experimental results show that the surface roughness of SUS304 stainless steel plate improves from 328 nm Ra to 14 nm Ra within 40 min.

scholarly journals Specific Loss Power of Co/Li/Zn-Mixed Ferrite Powders for Magnetic Hyperthermia

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2151
Author(s):  
Gabriele Barrera ◽  
Marco Coisson ◽  
Federica Celegato ◽  
Luca Martino ◽  
Priyanka Tiwari ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Cation Distribution ◽  
Biomedical Applications ◽  
Magnetic Measurements ◽  
Magnetic Hyperthermia ◽  
Alternating Magnetic Field ◽  
Specific Loss ◽  
Specific Loss Power ◽  
Auto Combustion

An important research effort on the design of the magnetic particles is increasingly required to optimize the heat generation in biomedical applications, such as magnetic hyperthermia and heat-assisted drug release, considering the severe restrictions for the human body’s exposure to an alternating magnetic field. Magnetic nanoparticles, considered in a broad sense as passive sensors, show the ability to detect an alternating magnetic field and to transduce it into a localized increase of temperature. In this context, the high biocompatibility, easy synthesis procedure and easily tunable magnetic properties of ferrite powders make them ideal candidates. In particular, the tailoring of their chemical composition and cation distribution allows the control of their magnetic properties, tuning them towards the strict demands of these heat-assisted biomedical applications. In this work, Co0.76Zn0.24Fe2O4, Li0.375Zn0.25Fe2.375O4 and ZnFe2O4 mixed-structure ferrite powders were synthesized in a ‘dry gel’ form by a sol-gel auto-combustion method. Their microstructural properties and cation distribution were obtained by X-ray diffraction characterization. Static and dynamic magnetic measurements were performed revealing the connection between the cation distribution and magnetic behavior. Particular attention was focused on the effect of Co2+ and Li+ ions on the magnetic properties at a magnetic field amplitude and the frequency values according to the practical demands of heat-assisted biomedical applications. In this context, the specific loss power (SLP) values were evaluated by ac-hysteresis losses and thermometric measurements at selected values of the dynamic magnetic fields.

Study on an Ultra-Precision Plane Magnetic Abrasive Finishing Process by Use of Alternating Magnetic Field

2013 ◽  
Vol 395-396 ◽  
pp. 985-989 ◽  
Author(s):  
Jin Zhong Wu ◽  
Yan Hua Zou
Keyword(s):  
Magnetic Field ◽  
Magnetic Particles ◽  
Water Soluble ◽  
Alternating Magnetic Field ◽  
Magnetic Flux Density ◽  
Magnetic Abrasive Finishing ◽  
Finishing Process ◽  
Abrasive Finishing ◽  
Ultra Precision ◽  
Surface Precision

In this paper, a new plane magnetic abrasive finishing process by using alternating magnetic field is proposed to improve the efficiency and surface precision. In alternating magnetic field, the forced direction of magnetic particles is changing. Therefore, magnetic particles could produce the up and down movement, which promote the scatter of magnetic particles , improve the roll of abrasive particles and enhance the utilization of abrasive. In order to know well the magnetic intensity distribution in processing area, measured the magnetic flux density. Finishing force is important to understand the mechanism of material removal, investigated to the finishing force and contrasted to the movement changes of magnetic particles in water-soluble finishing fluid and oily finishing fluid. A set of experimental devices have been designed to realize surface polishing on C2801 brass plate, the results proved the feasibility of this method, which can improve the workpiece surface quality.

Influence of Rotation on the Magnetization of Dilute Suspensions of Magnetic Particles

2015 ◽  
Vol 233-234 ◽  
pp. 302-305
Author(s):  
Alexander Tyatyushkin
Keyword(s):  
Magnetic Field ◽  
Magnetic Dipole ◽  
Uniform Magnetic Field ◽  
Magnetic Particles ◽  
Brownian Particle ◽  
Dipole Moments ◽  
Magnetization Vector ◽  
Alternating Magnetic Field ◽  
System Of Equations ◽  
Dilute Suspensions

The influence of rotation on the magnetization of a suspension of spherical magnetic particles in a uniform magnetic field is investigated theoretically with taking into account the inertial effects. A rotation of a single spherical non-Brownian particle with an embedded magnetic moment under action of a rotational flow of the ambient liquid in an applied uniform magnetic field is considered. The system of equations is obtained that determines the rotation of the particle and the instant orientation of its magnetic dipole moment with taking into account both the inertia of the particles and that of the dispersion liquid of the suspension. The magnetization vector of a suspension of non-Brownian spherical magnetic particles is found for the suspension rotating in a uniform constant magnetic field and for that rotating in a sufficiently weak uniform alternating magnetic field. The system of equations is obtained for the function of distribution over the orientations of the magnetic dipole moments for a suspension of Brownian spherical magnetic particles rotating in a uniform magnetic field. The solution to this system of equations is obtained for a suspension rotating in a sufficiently weak alternating magnetic field. With the use of this solution, the magnetization vector of the suspension is found.

scholarly journals Assessing the hyperthermic properties of magnetic heterostructures: the case of gold–iron oxide composites

2016 ◽  
Vol 6 (6) ◽  
pp. 20160058 ◽  
Author(s):  
Elvira Fantechi ◽  
Paula M. Castillo ◽  
Erika Conca ◽  
Francesca Cugia ◽  
Claudio Sangregorio ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Iron Oxide ◽  
Magnetic Fluid ◽  
Potassium Citrate ◽  
Alternating Magnetic Field ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Magnetic Fluid Hyperthermia ◽  
Transmission Electron ◽  
Oxide Composites

Gold–iron oxide composites were obtained by in situ reduction of an Au(III) precursor by an organic reductant (either potassium citrate or tiopronin) in a dispersion of preformed iron oxide ultrasmall magnetic (USM) nanoparticles. X-ray diffraction, transmission electron microscopy, chemical analysis and mid-infrared spectroscopy show the successful deposition of gold domains on the preformed magnetic nanoparticles, and the occurrence of either citrate or tiopronin as surface coating. The potential of the USM@Au nanoheterostructures as heat mediators for therapy through magnetic fluid hyperthermia was determined by calorimetric measurements under sample irradiation by an alternating magnetic field with intensity and frequency within the safe values for biomedical use. The USM@Au composites showed to be active heat mediators for magnetic fluid hyperthermia, leading to a rapid increase in temperature under exposure to an alternating magnetic field even under the very mild experimental conditions adopted, and their potential was assessed by determining their specific absorption rate (SAR) and compared with the pure iron oxide nanoparticles. Calorimetric investigation of the synthesized nanostructures enabled us to point out the effect of different experimental conditions on the SAR value, which is to date the parameter used for the assessment of the hyperthermic efficiency.

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